Responsibility that drives progress.
ista Progress Report 2025/26
Our sustainability strategy
Our sustainability strategy focuses on two key areas: our vehicle fleet and our electricity supply.
We aim to transition our vehicle fleet in Germany to 100% electric by the end of 2028. In the 2025 reporting year, we made significant progress towards this goal, further increasing the share of fully electric vehicles. At the same time, we are advancing the transition in other countries.
Renewable energy now accounts for the largest share of our energy supply, and its contribution to ista’s total electricity consumption continues to grow. While we have made substantial progress, we know there is still more to do. That is why we continuously review and refine our approach.
Our customers’ CO₂ emissions continue to fall
The positive trend continues: the carbon footprint of our customers in Germany is decreasing further. In 2024, the average CO₂ reduction for properties with heating cost billing (weather-adjusted) reached 13.11% compared with the 2018 baseline year. In 2023, the figure was 12.33%.
A key factor behind this development is transparent consumption data. It helps residents better understand their energy consumption and identify opportunities to improve efficiency.
Our fields of action
As part of our sustainability strategy, we have defined five fields of action which we are focusing on.
In the Environment field of action, we are committed to protecting the environment and mitigating climate change across all our sites. This includes actions such as the transition of our vehicle fleet to EVs and the switch to electricity from renewable sources at our sites.
The Markets field of action covers the development of our products and services. These make energy consumption transparent and can help to increase the energy efficiency of buildings. In this way, we support climate-conscious action in the buildings sector.
The Employees field of action describes our HR activities. Our goal is to create a working environment where everyone can give their best and to promote our employees' personal and professional development through comprehensive feedback processes, training and coaching – both in person and online.
We also take responsibility in the Partners field of action. Together with suppliers and business partners, we are working to reduce the carbon footprint in the supply chain.
In the Society field of action, we share our expertise in energy management and the efficient use of energy while encouraging our employees to get involved in the community. We do this by creating opportunities for them to spend part of their working hours on climate action and social projects.
Sustainability firmly embedded
Sustainability is firmly embedded within ista’s corporate structures. Our Management Board is directly responsible for the company’s sustainability activities and sets the targets we aim to achieve in the coming years.
Our Senior Programme Manager for Sustainability coordinates sustainability activities across the Group and works closely with the Management Board to oversee the implementation and ongoing advancement of our sustainability strategy.
In each country, Sustainability Delegates coordinate local activities. At the same time, they contribute their experience and insights from their own markets to the further development of the overall strategy.
Corporate sustainability software
We use centralised corporate sustainability software across the Group to manage our sustainability performance. It consolidates relevant data including energy consumption, emissions, mobility and staff development metrics.
The software enables us to continuously monitor our progress. It helps us create transparency and a robust basis for informed decisions.
Using renewable energy
Wherever possible, we use electricity from renewable sources in our buildings. In the 2025 reporting year, electricity from renewable sources accounted for 75.2% of the company's total power consumption. This means that renewable energy makes up a large proportion of our energy supplies.
International standards and clear policies
ista consistently aligns its business practices with international standards and binding internal policies. The United Nations Global Compact provides key guidance in this regard. By signing up to it, we have committed to actively implementing core principles including the protection of human rights, decent working conditions, and environmental and anti-corruption measures.
Code of Conduct
Our global Code of Conduct sets out the binding standards of conduct for all employees. It covers a range of topics, including human rights, working conditions, data protection and anti-corruption. The Code is supplemented by additional internal policies, including those governing interactions with business partners and compliance with competition law.
Digital compliance training
To ensure the content of the Code of Conduct is effectively communicated, Corporate Compliance provides a web-based training course on the Group-wide learning platform. All employees are required to complete this training. The courses are designed to be practical and easy to apply in day-to-day work. Another mandatory e-learning module provides in-depth content on anti-corruption, fair competition and the standards required of business partners. All training courses are regularly updated and repeated annually.
Systematic compliance management
Our Group-wide compliance management system ensures that all relevant requirements are met. The effectiveness and adequacy of this system have been confirmed by an independent audit firm in accordance with the IDW PS 980 audit standard.
Standards of conduct for business partners
Our integrity requirements apply throughout the entire value chain. We therefore also expect our suppliers and service providers worldwide to comply with fundamental ESG standards. Our binding Business Partner Code, which is based on the principles of the UN Global Compact and the requirements of the German Supply Chain Due Diligence Act, serves as the guiding framework.